You can check out the source code in SVN. There is still a lot of work to
do, but both the demo and full game run great. If you don't already own the
full game, you may have a hard time finding it for sale, as copies of the
game are pretty scarce these days. Be sure to apply the 1.2 patch for the
full version, if you have not already. If you just want to try the demo, you
can download it from places like here or here (you don't have to apply the
patch for the demo).